Malaria in Developing Countries (SQA National 5 Geography): Revision Note

Causes of Malaria

What is malaria?

• Malaria is a communicable disease that is spread by certain types of infected mosquitoes

• Infected female Anopheles mosquitoes carry a parasite which spreads the disease

• If a person is bitten by the infected mosquito, the parasite can enter the person’s bloodstream

• The parasites rapidly reproduce, causing a flu-like illness 

• Malaria is preventable and treatable, but can be fatal if untreated

Global distribution of malaria

• More than 280 million people around the world are living with malaria 

• The majority of infections are found in tropical and subtropical regions 

• In 2024, 610,000 people died of malaria

• Malaria is most prevalent in developing countries

  • This is mainly due to the warmer climates, which lead to larger numbers of mosquitoes and poorer access to healthcare

  • In 2024, 95% of malaria cases and deaths were in sub-Saharan Africa

• Malaria has been eradicated from many developed countries

Causes of malaria

Environmental factors

• Hot and wet climates in tropical and subtropical regions allow mosquitoes to breed more quickly 

  • Temperatures need to be between 15 and 35°C for the mosquito and the parasite to develop

  • High humidity helps mosquitoes to have longer lifespans

  • Consistently high temperatures and humidity allow mosquitoes to survive all year round and bite more frequently, enabling them to transmit the disease more effectively

• Mosquitoes need standing water, e.g. a lake, pond or puddle to lay eggs 

  • Frequent rainfall and poor drainage lead to build-ups of standing water

Human factors

• Poor-quality housing allows easier access for mosquitoes

  • For example, a lack of window screens or mosquito nets makes it difficult to avoid mosquito bites

• Global travel and migration allow the disease to spread

• Poor sanitation can lead to more areas of standing water

• Humans create areas of standing water, for example, by building dams

• Poverty makes people more vulnerable to malaria by reducing access to prevention and treatment

• Children are particularly vulnerable to malaria

  • Children under 5 years account for around three-quarters of malaria deaths in sub-Saharan Africa

Effects of Malaria

Effects of malaria on people

• Symptoms first appear about 7-10 days after an infected mosquito bite

• The most common symptoms include:

  • Fever and sweating

  • Chills and shivering

  • Headache

  • Extreme tiredness

  • Muscle aches

  • Nausea, vomiting and diarrhoea

• If not treated promptly, malaria can progress into a severe illness

• More severe symptoms include:

  • Impaired consciousness

  • Confusion

  • Convulsions

  • Breathing difficulties

  • Dark or bloody urine, indicating kidney failure

  • Jaundice (yellowing of eyes and skin), indicating liver failure

  • Abnormal bleeding

• Ultimately, if not treated, malaria will lead to multiple organ failure and death

Effects of malaria on communities and countries

• Lower life expectancies

  • The death of loved ones causes grief for families and negatively affects their health and well-being

• Poor health and long-term sickness

  • This leads to a loss of income for the person and their family, causing them to fall into poverty

    • This may mean that families can’t afford to send their children to school, so they miss out on an education

    • They may not be able to afford sufficient food, leading to malnutrition and hunger

  • Crops may be left unharvested if farm workers are too ill to gather them in

• More sick days or people being unable to work

  • This reduces productivity and profits for businesses

  • This leads to lower tax income for the government

• More pressure on the health system

  • There may be a shortage of medication and doctors, leading to increased death rates

  • Money needs to be diverted away from other sectors, such as education, which could lead to slower progress in those areas

• Tourists may be reluctant to visit the country because of the malaria threat

  • This can lead to further loss of income for the national economy

Strategies to manage malaria

Medicines and vaccinations 

• Antimalarial drugs such as Malarone kill the parasite that causes the disease

• Since 2021, vaccinations such as Mosquirix have been recommended for young children in high-risk regions to reduce the chances of them catching malaria

Preventing mosquito bites

• Use of mosquito nets and window screens

• Protective clothing and mosquito repellents, which contain DEET

• Spraying with insecticides, such as malathion, to kill mosquitoes

• Removing standing water to prevent mosquitoes from breeding

  • For example, by planting eucalyptus trees, which soak up a lot of water

• Killing mosquito larvae in standing water

  • For example, by adding fish, which eat them, or mustard seeds, which drag them down and drown them

• Education to teach people how to eradicate mosquitoes and protect themselves from bites

• Genetic engineering to produce sterile male mosquitoes which cannot breed or carry the malaria parasite

  • Over time, as they mate with infected female mosquitoes, the number of mosquitoes declines and fewer mosquitoes can spread malaria